Section A [40 marks] Rubries: Answer all the questions in this sect Question 1 Os O.. oh B c D qi) Ss - Gi) (b) K L dj) K L Ci | = Plants = Carbon dioxide in the atmosphere Animals Dead/decaying organisms/organic matter 4marks — Photosynthesis = Decay/decomposition - Combustion/burning diene Raising of livestock Growing of crops Burning of wood Burning of fossil fuels/coal/industrial pollution Reducing amount of forest cover/deforestation Any 3 x 1=3 marks Land rotation qd) Crop rotation Q) The farmer moves from one farmland to another The farmer moves /rotates the crops from one plot to another(1) The soil regains its fertility / prevents soil exhaustion fhere is control in the build-up pests and diseases od yield It helps to maintain g saves money Any 2x 1=2 marks(c) (iv) (v) w@ (ii) Time, energy and money is wasted in clearing new land each time land is abandoned. System does not encourage large scale farming, There is rampant deforestation Cultivated lands are generally small and scattered Land is getting scarce / a growing population Any 3x1 =3 marks Leguminous crops a) 3 Stair case - Ladder Plank of wood at an angle B Hill : Ramps ete Sewews oF Any 3 1=3 marks (a) work output LxLd/ qa =100x5 = 500 J qd) (8) — Work input ExeEd / Q) = 400 x 10 = 4000 J a (y) Efficiency Work output x 100% Work input a 500 x 100% 4000 @ 8 in &@m w Separation of mixtures (1) Cools the vaporized components of the mixture (1) back to liquid (1) . vi - Bar magnet attracts the magnetic material of ue on ol mixture (1) in order to separate it from the non-mag @ ou component (1) (2) I~ qJeglsfethanol and water / kerosene and disel oi! (2) vi iron filings and powdered Sulphur (2) (iv) To ensure complete condensation of the vapour (1) QUESTION 1 TOTAL = [40 MARKS| SECTION B Answer three (3) questions only from this section estion 2 @ @ - By ironing in bulk lacks : Switching off lights{When not in use = Switching off gadgets when not in use - a8 Ups ving Any 3x 1=3 marks fi) E=Pxe a) 4000x121) 4kW x 12h (1) =48kWh (1) OR E=Pxt @ = 4000 x 12x 60x60 (2) 172800000 / 1.72 x 108 joules /J ayib) (ii) oO @ (i) @ Question 3 @ @ methy! orange methyl red t phenolphalein og no~twbe ane ona? litmus universal indicator Any 2x1 =2 marks Litmus ~ red Methyl orange -red/pink == Dy clone Methyl red — red/pink Phenolphthalein - colourless Universal indicator ~ orange / yellow Any 2x 1=2 marks Waste management / recycling Io wse Investing in renewable energy Adapting to the effects of climate change Prioritizing human health Use resources more efficiently = Afforestation Use of public transport / electric vehicle ‘Any 4.x 1=4 marks Hho (IV) 2 anol * carbon dioxide - methane nitrous oxide / nitrogen (1) oxide ‘Any 2.x 1=2 marks Choose an area / compost bin / home made enclosure / dig a pit ‘Add green material / vegetable / scrap / fruit peels / grass / dry straw ex° Put materials in layers Sprinkle water Tum pile occasionally Any 3x 1=3 marks QUESTION 2 TOTAL = (20 MARKS] Feather Blood mee 2 marks Any 2a Sorghum . Millet Maize ‘Wheat aa Rice =2 ma Wheat bran any? «1 : where it condenses Ife 0) A i (b) Water evaporates from water bodies into the aumospher recipitation) (): Clouds (1), and falls back into the ‘earth's surface 8 © ire to BIVe 1s (1) which tans! this then flows into water bodies (1) and taken uP PY pla water vapour (1) 6 marks 2 marks «© wa Vinegar - ethanoic acid (1) and water qd) 3 marks Air - nitrogen (1) and oxygen @ (ii) Vinegar. = ~_ water is the solvent a Air = nitrogen is the solvent (1) @d @& - Extreme / cold temperatures - No oxygen = No water - Far away from the sun ~ absence of solid surface toxic radiations / gases - strong magnetic field Any 2x 1=2 marks (i) - Saturn - Uranus Neptune Any 2x 1=2 marks QUESTION 3 TOTAL = (20 MARKS] Question 4 @ @ - sharpening the knife, ressure then ir t cuts easil 3x 1=3 marks fOxt A i xtoF Bly 10.000 Fs (1) CD bon (bia(b) (©) id) @ (ii) (i) iii) Collect the soil sample (1) Add disti distilled water and shake gently, and allow to sett le! Ad id few drops of universal indicator / pH meter’ hart |) Mat the resulting colour with the imate / read the pH of the soil samp! NB: Correct sequen 6 It means the blood pressure of the )) and the pressu! wm (systolic pressure) (1) 90 mmHg (diastolic pressure) Exercising regular! : Easing stress = Ensuring regular Ete el < ly Eating healthy diets Reducing salt intake eck-UPS » cies FE piglet GS Has high palatability to animals Has laxative ability Has high nutrient content Easily digestible Long shelf-life Ete QUESTION 4 TOTAL = Organic farming animal based materials (1 fertilizers / bi standard colour cl te from the chart () ) score e to a marks eart beats 1S 150 mmHg eart rests 1S patient when the bi when the h ire of the patient ole any 3* Any 3x1 =3 marks [20 MARKS] ng process; ) in the farmii iological pesticides By using plant and chemicals / using organic 2 marks without use of agro: Mixed farming By growing of crops and © at the same time f f two ¢ aising of animals on the same farm / plot 2 marks he same piece of land, (1) t the same time (dy) 2 marks y=3 marks ao to) ii) i) w (ii) @ Gi) Oil and water - Heterogeneous (iy) Salt and water - Homogeneous a) Ethanol and water - Homogeneous a - Energy from the sun is continuous / constantly replenished a Energy from the sun does not get exhausted / inexhaustible within a human time scale / non-depletable (a) [ Temperal itu —— Measure of / Degree of hotness ofa body Measured in Kelvin /°C ‘Measured using a thermometer | Rises when heated and falls [Me i [> Measured using a calorimeter [> Flows from hot body to cold body | when cooled __ =e ‘Any 3x 1=3 marks Leaching During heavy rainfall, nitrates in the soil are washed out of the root zone of plants (1) . and cannot be taken in by animals, (1) preventing the return of the nitrogen into the soil as nitrites (1) 3 marks Removal of leguminous plants : this results in the removal of nitrogen-fixing bacteria (1) thereby preventing the conversion of atmospheric nitrogen to ammonia (1) eventually denying the soil of nitrates and subsequently interrupting the Cyele (1) 3 marks QUESTION 5 TOTAL = (20 MARKS]